This invention relates to an improvement in roofing tile, and more particularly, to flat shingle style roofing tile having new and improved water drainage features adapted to be laid over an underlayment in a series of rows on a roof.
In prior roofing tile designs, water drainage has been provided along longitudinal gutters formed by lateral flanges used to lock tiles together in transverse rows. Such arrangements are described, for example, in U.S. Pat. No. 592,474 to Merrill and U.S. Pat. No. 2,510,416 to Pretty. Alternatively, other tile designs have incorporated drainage channels on the top surface of the tile, as disclosed, for example, in U.S. Pat. No. 426,584 to Donaldson.
In conventional roofing systems, an underlayment comprising asphalt roofing felt is laid over a plywood underroofing. Wooden strips, or battens, are then laid in transverse rows over the underlayment, and the roofing tiles are nailed, through nail holes provided in the tile, directly to the batten. Some conventional systems secure the tiles to the roof by nailing the tile directly through the asphalt underlayment to the plywood underroofing without using battens.
A disadvantage of these prior roofing tile designs has been the tendency for the ends of the tiles to form dams against the roof underlayment, thereby permitting water to pool on the underlayment. Additionally, the nail holes through the roof underlayment tend to permit the accumulated water to seep beneath the underlayment. Industry experts are in agreement that a major cause for concrete tile roofing system failures has been moisture beneath the tile and the underlayment which is not disappated, and which accelerates the deterioration of the underlayment, leading to roof leaks.
Past roofing tile designs have made no special provisions to prevent the accumulation of water beneath roofing tiles on the roofing underlayment. This has resulted in roofs failing in as early as 12 years, and more commonly in 15 to 20 years. A well-designed and properly installed concrete roofing tile system should last well in excess of 20 years.
Accordingly, it is an object of the invention to provide an improved flat shingle style concrete roofing tile having a new drainage feature which will minimize the accumulation of water beneath the tile, and thereby prolong the useful life of the roof.
It is a further object of the invention to provide a flat shingle style concrete roofing tile wherein no structural considerations will be reflected on the surface of the tile.